European Commission head Jose Barroso and European Union President Herman van Rompuy said they strongly welcomed Thursday's vote.

"This was the second, decisive step Greece needed to take in order to return to a sustainable path," they said in a joint statement from Brussels. "In very difficult circumstances, it was another act of national responsibility."

They said the conditions "are now in place" for a decision on the release of a fifth round of emergency funds to Greece, part of a multi-billion euro deal agreed last year, and for "rapid progress" on a second proposed bailout.

Following the vote, the Greek civil servants' union ADEDY called another rally outside Parliament for Thursday evening.

Before Wednesday's vote, small numbers of demonstrators hurled stones at police, chanted, waved Greek flags and set small fires to protest the austerity measures, which include new taxes and job cuts.

At least 19 police officers were injured Wednesday, police said.

European and international lenders agreed last year to give Greece a $156 billion bailout package as its deficit soared, but were threatening to hold up an installment of $17 billion due soon.

Greece has debt payments coming due in mid-July and needs the $17 billion in emergency funds to be able to pay them -- but lenders, including the International Monetary Fund and the EU, had demanded that it approve the austerity measures in order to get the loan.

A default by Greece would send shock waves through the European banking sector and potentially dent global economic confidence.

German Chancellor Angela Merkel called Wednesday's passage of the austerity measures "really good news," German government spokesman Steffen Seibert said on Twitter.

Eurogroup chairman Jean-Claude Juncker also welcomed the news, saying: "I'm very happy and relieved that the Greek Parliament followed the government and voted in favour of a new program of structural reforms and budgetary adjustment."

Unions oppose the austerity package, but its backers say it is essential to the stability of the Greek economy, the euro, and the global financial system.

Protesters lament that the cuts are being carried out on the backs of those who can afford it least.